This template may be used on any page formatted as '(Year) in (Place)' (e.g. 1967 in Australia). But as of 2021-10-06 it is common only on pages about 'Year in Australia'.
Monarch: Generally contained within the article, but if not, see here for a good list.
Governor-General: Generally contained within the article, but if not, see here for a good list.
Prime Minister: Generally contained within the article, but if not, see here for a good list.
Population: See here (since 1901) or here (since 1788). Some older results do not include indigenous peoples. 'Since 1901' generally contains this data.